Kyle Juszczyk trudged off the Ravens' practice field as a rookie fullback a year ago, thoroughly frustrated after a training camp blocking drill in which he was stonewalled repeatedly by linebackers and safeties.

In the middle of Juszczyk's unconvincing audition as an inexperienced lead blocker, veteran rush linebacker Terrell Suggs shouted that Ravens general manager Ozzie Newsome needed to bring back Pro Bowl fullback Vonta Leach. Three days later, Leach was signed to return as the Ravens' starting fullback. Juszczyk was relegated to a special teams role and played just four snaps on offense during his first NFL season.

"We've joked about that the past couple of weeks, me and [tight end] Dennis Pitta; we say that was the day I lost my job, because I think the next day Vonta came in," Juszczyk said. "That was a rough day. I think that was my 'Welcome to the NFL' moment. It's amazing what can change in a year. I definitely learned something from Vonta: 'Low man wins.' "

Juszczyk demonstrated that knowledge while matched up against Suggs on Thursday. Stronger and leaner than during his rookie season, Juszczyk delivered a resounding block that knocked the Pro Bowler to the ground.

"It was definitely a confidence booster," Juszczyk said. "I was blocking Suggs on the edge. I don't know if he tripped or whatever, but he ended up on his back. I'm going to take credit for it.

"I feel like I've drastically improved as a blocker. I knew that was going to be the biggest thing I had to work on this offseason, and I knew that was what I would be judged on the most when I came out here."

The Ravens felt comfortable enough with Juszczyk, a fourth-round draft pick last year from Harvard, to release Leach in February. Now Juszczyk is establishing himself as the unchallenged starter and is expected to have a versatile role in offensive coordinator Gary Kubiak's system.

NFL offenses are moving toward fullbacks such as Juszczyk, an athletic, 6-foot-1, 248-pound hybrid. He played tight end, H-back and slot receiver in the Ivy League, catching 125 career passes for 1,576 yards and 22 touchdowns. Juszczyk represents a change of style from the old-school, battering-ram approach of Leach, who played five seasons for Kubiak with the Houston Texans.

"The fullback is one of the most important roles on the offense, outside of the quarterback," Leach said in a telephone interview. "Everything works off play-action, and Coach Kubiak has been very successful in this league with how he uses the fullback. They'll spread Kyle out and have him run routes and use the kind of skills that he has working for him.

"I think Kyle will have a pretty good run with the Ravens. He's a smart guy and a tough guy who can take coaching. He listened well and he wants to be good. He doesn't act like he has everything already figured out. I think he's ready."

Juszczyk reminds Kubiak of fullback James Casey, who caught 34 passes for 330 yards and three touchdowns in 2012 for the Texans under the former Houston head coach. Casey signed a three-year, $14.6 million contract with the Philadelphia Eagles last year.

"It kind of started with Vonta. Vonta was really the big-banger-type player," Kubiak said. "Kyle is a little bit different. I've had a couple of athletic guys in the past, and Kyle fits that mold. So it gives me the ability to move him around and so some things.

"I've been impressed with Kyle. He's had an excellent offseason. He's very athletic. He has good hands, and he's a threat catching the ball. He's responded also to the dirty work, which is something he's going to have to do."

With his quickness, hands and route-running ability, Juszczyk has proved to be a difficult assignment for defensive backs and linebackers during training camp. He said he understands and appreciates the comparisons to Casey.

"I've seen those similar qualities between myself and James Casey because during the whole draft process, a lot of people said I reminded them of him," Juszczyk said. "I think it's a compliment because he's a great player and he's one of those guys that can do a lot of different things."

At practice, Juszczyk has been in constant motion. From snap to snap, he could be lined up as a traditional fullback in the I-formation, blocking for running back Ray Rice or flexed outside as an extra wide receiver.

"I feel extremely comfortable in this offense because this is so similar to what we did at Harvard," Juszczyk said. "Once we got more into spreading me out and running routes, this is a total comfort zone. I'm just doing what I did in college. I'm loving it."

Juszczyk was named the Ivy League Offensive Player of the Year as a senior, when he caught 52 passes for 706 yards and eight touchdowns. When Juszczyk first met Kubiak, the first-year coordinator told him he could be in line for similar production.

"Coach Kubiak mentioned early on, 'Juice, I could see you getting 40, 50 catches this year,' " Juszczyk said. "I think that's a very reasonable goal and something to strive for."

Primarily because of his Ivy League background, Juszczyk said he has heard plenty of taunts in games and practices about whether he has the requisite toughness to succeed in the NFL.

"Not a day goes by that the Harvard thing doesn't get brought up," Juszczyk said. "I'm sure it's something I'll continue to battle the rest of my career. I don't know if you want to print what I've heard in games. Basically, a lot of them say, 'What's this white guy from Harvard going to do?' It definitely motivates you."

Although Juszczyk entered the NFL with impressive measurables — he ran the 40-yard dash in 4.71 seconds, registered a 37-inch vertical leap and bench-pressed 225 pounds 24 times at Harvard's Pro Day — he felt the need to make some physical improvements this offseason.

Since the end of last season, when he weighed 250 pounds, Juszczyk has cut his body-fat percentage almost in half. He ended last season with 18 percent body fat; he's now down to 10 percent.

"I feel a lot better," Juszczyk said. "I'm a lot more efficient at this weight, a few pounds lighter."

Juszczyk inherited Leach's job, and his No. 44 jersey, this offseason. He's aware that Leach left behind a big legacy at the position in Baltimore. Entering the second year of a four-year, $2.46 million contract, Juszczyk is intent on living up to Leach's high standard.

"I learned a lot from Vonta," Juszczyk said. "One of the great things about Vonta is there was never any sort of beef between us. He kind of took me under his wing and said, 'Listen, follow me, Juice, and I'll show you a lot of things.' He did a great job of mentoring me. I can't wait for the season to start and show how I've improved."